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0d66548a OH |
1 | /* |
2 | * af_can.c - Protocol family CAN core module | |
3 | * (used by different CAN protocol modules) | |
4 | * | |
5 | * Copyright (c) 2002-2007 Volkswagen Group Electronic Research | |
6 | * All rights reserved. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. Neither the name of Volkswagen nor the names of its contributors | |
17 | * may be used to endorse or promote products derived from this software | |
18 | * without specific prior written permission. | |
19 | * | |
20 | * Alternatively, provided that this notice is retained in full, this | |
21 | * software may be distributed under the terms of the GNU General | |
22 | * Public License ("GPL") version 2, in which case the provisions of the | |
23 | * GPL apply INSTEAD OF those given above. | |
24 | * | |
25 | * The provided data structures and external interfaces from this code | |
26 | * are not restricted to be used by modules with a GPL compatible license. | |
27 | * | |
28 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
29 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
30 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
31 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
32 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
33 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
34 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
35 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
36 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
37 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
38 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH | |
39 | * DAMAGE. | |
40 | * | |
0d66548a OH |
41 | */ |
42 | ||
43 | #include <linux/module.h> | |
44 | #include <linux/init.h> | |
45 | #include <linux/kmod.h> | |
46 | #include <linux/slab.h> | |
47 | #include <linux/list.h> | |
48 | #include <linux/spinlock.h> | |
49 | #include <linux/rcupdate.h> | |
50 | #include <linux/uaccess.h> | |
51 | #include <linux/net.h> | |
52 | #include <linux/netdevice.h> | |
53 | #include <linux/socket.h> | |
54 | #include <linux/if_ether.h> | |
55 | #include <linux/if_arp.h> | |
56 | #include <linux/skbuff.h> | |
57 | #include <linux/can.h> | |
58 | #include <linux/can/core.h> | |
d751e623 | 59 | #include <linux/ratelimit.h> |
0d66548a OH |
60 | #include <net/net_namespace.h> |
61 | #include <net/sock.h> | |
62 | ||
63 | #include "af_can.h" | |
64 | ||
65 | static __initdata const char banner[] = KERN_INFO | |
66 | "can: controller area network core (" CAN_VERSION_STRING ")\n"; | |
67 | ||
68 | MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); | |
69 | MODULE_LICENSE("Dual BSD/GPL"); | |
70 | MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, " | |
71 | "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); | |
72 | ||
73 | MODULE_ALIAS_NETPROTO(PF_CAN); | |
74 | ||
75 | static int stats_timer __read_mostly = 1; | |
76 | module_param(stats_timer, int, S_IRUGO); | |
77 | MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); | |
78 | ||
20dd3850 OH |
79 | /* receive filters subscribed for 'all' CAN devices */ |
80 | struct dev_rcv_lists can_rx_alldev_list; | |
0d66548a OH |
81 | static DEFINE_SPINLOCK(can_rcvlists_lock); |
82 | ||
83 | static struct kmem_cache *rcv_cache __read_mostly; | |
84 | ||
85 | /* table of registered CAN protocols */ | |
1650629d | 86 | static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly; |
1ca050d9 | 87 | static DEFINE_MUTEX(proto_tab_lock); |
0d66548a OH |
88 | |
89 | struct timer_list can_stattimer; /* timer for statistics update */ | |
90 | struct s_stats can_stats; /* packet statistics */ | |
91 | struct s_pstats can_pstats; /* receive list statistics */ | |
92 | ||
93 | /* | |
94 | * af_can socket functions | |
95 | */ | |
96 | ||
53914b67 | 97 | int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
0d66548a OH |
98 | { |
99 | struct sock *sk = sock->sk; | |
100 | ||
101 | switch (cmd) { | |
102 | ||
103 | case SIOCGSTAMP: | |
104 | return sock_get_timestamp(sk, (struct timeval __user *)arg); | |
105 | ||
106 | default: | |
107 | return -ENOIOCTLCMD; | |
108 | } | |
109 | } | |
53914b67 | 110 | EXPORT_SYMBOL(can_ioctl); |
0d66548a OH |
111 | |
112 | static void can_sock_destruct(struct sock *sk) | |
113 | { | |
114 | skb_queue_purge(&sk->sk_receive_queue); | |
115 | } | |
116 | ||
c8d55a9d | 117 | static const struct can_proto *can_get_proto(int protocol) |
1ca050d9 | 118 | { |
1650629d | 119 | const struct can_proto *cp; |
1ca050d9 OH |
120 | |
121 | rcu_read_lock(); | |
122 | cp = rcu_dereference(proto_tab[protocol]); | |
123 | if (cp && !try_module_get(cp->prot->owner)) | |
124 | cp = NULL; | |
125 | rcu_read_unlock(); | |
126 | ||
127 | return cp; | |
128 | } | |
129 | ||
c8d55a9d KVD |
130 | static inline void can_put_proto(const struct can_proto *cp) |
131 | { | |
132 | module_put(cp->prot->owner); | |
133 | } | |
134 | ||
3f378b68 EP |
135 | static int can_create(struct net *net, struct socket *sock, int protocol, |
136 | int kern) | |
0d66548a OH |
137 | { |
138 | struct sock *sk; | |
1650629d | 139 | const struct can_proto *cp; |
0d66548a OH |
140 | int err = 0; |
141 | ||
142 | sock->state = SS_UNCONNECTED; | |
143 | ||
144 | if (protocol < 0 || protocol >= CAN_NPROTO) | |
145 | return -EINVAL; | |
146 | ||
09ad9bc7 | 147 | if (!net_eq(net, &init_net)) |
0d66548a OH |
148 | return -EAFNOSUPPORT; |
149 | ||
c8d55a9d | 150 | cp = can_get_proto(protocol); |
1ca050d9 | 151 | |
95a5afca | 152 | #ifdef CONFIG_MODULES |
1ca050d9 OH |
153 | if (!cp) { |
154 | /* try to load protocol module if kernel is modular */ | |
155 | ||
5423dd67 | 156 | err = request_module("can-proto-%d", protocol); |
0d66548a OH |
157 | |
158 | /* | |
159 | * In case of error we only print a message but don't | |
160 | * return the error code immediately. Below we will | |
161 | * return -EPROTONOSUPPORT | |
162 | */ | |
d751e623 MZ |
163 | if (err) |
164 | printk_ratelimited(KERN_ERR "can: request_module " | |
5423dd67 | 165 | "(can-proto-%d) failed.\n", protocol); |
1ca050d9 | 166 | |
c8d55a9d | 167 | cp = can_get_proto(protocol); |
0d66548a | 168 | } |
5423dd67 | 169 | #endif |
0d66548a | 170 | |
0d66548a OH |
171 | /* check for available protocol and correct usage */ |
172 | ||
173 | if (!cp) | |
174 | return -EPROTONOSUPPORT; | |
175 | ||
176 | if (cp->type != sock->type) { | |
1ca050d9 | 177 | err = -EPROTOTYPE; |
0d66548a OH |
178 | goto errout; |
179 | } | |
180 | ||
0d66548a OH |
181 | sock->ops = cp->ops; |
182 | ||
183 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot); | |
184 | if (!sk) { | |
185 | err = -ENOMEM; | |
186 | goto errout; | |
187 | } | |
188 | ||
189 | sock_init_data(sock, sk); | |
190 | sk->sk_destruct = can_sock_destruct; | |
191 | ||
192 | if (sk->sk_prot->init) | |
193 | err = sk->sk_prot->init(sk); | |
194 | ||
195 | if (err) { | |
196 | /* release sk on errors */ | |
197 | sock_orphan(sk); | |
198 | sock_put(sk); | |
199 | } | |
200 | ||
201 | errout: | |
c8d55a9d | 202 | can_put_proto(cp); |
0d66548a OH |
203 | return err; |
204 | } | |
205 | ||
206 | /* | |
207 | * af_can tx path | |
208 | */ | |
209 | ||
210 | /** | |
211 | * can_send - transmit a CAN frame (optional with local loopback) | |
212 | * @skb: pointer to socket buffer with CAN frame in data section | |
213 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
214 | * | |
481a8199 OH |
215 | * Due to the loopback this routine must not be called from hardirq context. |
216 | * | |
0d66548a OH |
217 | * Return: |
218 | * 0 on success | |
219 | * -ENETDOWN when the selected interface is down | |
220 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
221 | * -ENOMEM when local loopback failed at calling skb_clone() | |
222 | * -EPERM when trying to send on a non-CAN interface | |
7f2d38eb | 223 | * -EINVAL when the skb->data does not contain a valid CAN frame |
0d66548a OH |
224 | */ |
225 | int can_send(struct sk_buff *skb, int loop) | |
226 | { | |
c2ab7ac2 | 227 | struct sk_buff *newskb = NULL; |
7f2d38eb | 228 | struct can_frame *cf = (struct can_frame *)skb->data; |
0d66548a OH |
229 | int err; |
230 | ||
7f2d38eb OH |
231 | if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) { |
232 | kfree_skb(skb); | |
233 | return -EINVAL; | |
234 | } | |
235 | ||
0d66548a OH |
236 | if (skb->dev->type != ARPHRD_CAN) { |
237 | kfree_skb(skb); | |
238 | return -EPERM; | |
239 | } | |
240 | ||
241 | if (!(skb->dev->flags & IFF_UP)) { | |
242 | kfree_skb(skb); | |
243 | return -ENETDOWN; | |
244 | } | |
245 | ||
246 | skb->protocol = htons(ETH_P_CAN); | |
247 | skb_reset_network_header(skb); | |
248 | skb_reset_transport_header(skb); | |
249 | ||
250 | if (loop) { | |
251 | /* local loopback of sent CAN frames */ | |
252 | ||
253 | /* indication for the CAN driver: do loopback */ | |
254 | skb->pkt_type = PACKET_LOOPBACK; | |
255 | ||
256 | /* | |
257 | * The reference to the originating sock may be required | |
258 | * by the receiving socket to check whether the frame is | |
259 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS | |
260 | * Therefore we have to ensure that skb->sk remains the | |
261 | * reference to the originating sock by restoring skb->sk | |
262 | * after each skb_clone() or skb_orphan() usage. | |
263 | */ | |
264 | ||
265 | if (!(skb->dev->flags & IFF_ECHO)) { | |
266 | /* | |
267 | * If the interface is not capable to do loopback | |
268 | * itself, we do it here. | |
269 | */ | |
c2ab7ac2 | 270 | newskb = skb_clone(skb, GFP_ATOMIC); |
0d66548a OH |
271 | if (!newskb) { |
272 | kfree_skb(skb); | |
273 | return -ENOMEM; | |
274 | } | |
275 | ||
276 | newskb->sk = skb->sk; | |
277 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
278 | newskb->pkt_type = PACKET_BROADCAST; | |
0d66548a OH |
279 | } |
280 | } else { | |
281 | /* indication for the CAN driver: no loopback required */ | |
282 | skb->pkt_type = PACKET_HOST; | |
283 | } | |
284 | ||
285 | /* send to netdevice */ | |
286 | err = dev_queue_xmit(skb); | |
287 | if (err > 0) | |
288 | err = net_xmit_errno(err); | |
289 | ||
c2ab7ac2 | 290 | if (err) { |
ce030edf | 291 | kfree_skb(newskb); |
c2ab7ac2 OH |
292 | return err; |
293 | } | |
294 | ||
295 | if (newskb) | |
481a8199 | 296 | netif_rx_ni(newskb); |
c2ab7ac2 | 297 | |
0d66548a OH |
298 | /* update statistics */ |
299 | can_stats.tx_frames++; | |
300 | can_stats.tx_frames_delta++; | |
301 | ||
c2ab7ac2 | 302 | return 0; |
0d66548a OH |
303 | } |
304 | EXPORT_SYMBOL(can_send); | |
305 | ||
306 | /* | |
307 | * af_can rx path | |
308 | */ | |
309 | ||
310 | static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) | |
311 | { | |
20dd3850 OH |
312 | if (!dev) |
313 | return &can_rx_alldev_list; | |
314 | else | |
315 | return (struct dev_rcv_lists *)dev->ml_priv; | |
0d66548a OH |
316 | } |
317 | ||
d253eee2 OH |
318 | /** |
319 | * find_rcv_list - determine optimal filterlist inside device filter struct | |
320 | * @can_id: pointer to CAN identifier of a given can_filter | |
321 | * @mask: pointer to CAN mask of a given can_filter | |
322 | * @d: pointer to the device filter struct | |
323 | * | |
324 | * Description: | |
325 | * Returns the optimal filterlist to reduce the filter handling in the | |
326 | * receive path. This function is called by service functions that need | |
327 | * to register or unregister a can_filter in the filter lists. | |
328 | * | |
329 | * A filter matches in general, when | |
330 | * | |
331 | * <received_can_id> & mask == can_id & mask | |
332 | * | |
333 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe | |
334 | * relevant bits for the filter. | |
335 | * | |
336 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
337 | * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames | |
338 | * there is a special filterlist and a special rx path filter handling. | |
339 | * | |
340 | * Return: | |
341 | * Pointer to optimal filterlist for the given can_id/mask pair. | |
342 | * Constistency checked mask. | |
343 | * Reduced can_id to have a preprocessed filter compare value. | |
344 | */ | |
0d66548a OH |
345 | static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, |
346 | struct dev_rcv_lists *d) | |
347 | { | |
348 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
349 | ||
d253eee2 | 350 | /* filter for error frames in extra filterlist */ |
0d66548a | 351 | if (*mask & CAN_ERR_FLAG) { |
d253eee2 | 352 | /* clear CAN_ERR_FLAG in filter entry */ |
0d66548a OH |
353 | *mask &= CAN_ERR_MASK; |
354 | return &d->rx[RX_ERR]; | |
355 | } | |
356 | ||
d253eee2 OH |
357 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
358 | ||
359 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) | |
360 | ||
361 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ | |
362 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) | |
363 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); | |
0d66548a OH |
364 | |
365 | /* reduce condition testing at receive time */ | |
366 | *can_id &= *mask; | |
367 | ||
368 | /* inverse can_id/can_mask filter */ | |
369 | if (inv) | |
370 | return &d->rx[RX_INV]; | |
371 | ||
372 | /* mask == 0 => no condition testing at receive time */ | |
373 | if (!(*mask)) | |
374 | return &d->rx[RX_ALL]; | |
375 | ||
d253eee2 | 376 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
f64f9e71 JP |
377 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) && |
378 | !(*can_id & CAN_RTR_FLAG)) { | |
d253eee2 OH |
379 | |
380 | if (*can_id & CAN_EFF_FLAG) { | |
381 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) { | |
382 | /* RFC: a future use-case for hash-tables? */ | |
383 | return &d->rx[RX_EFF]; | |
384 | } | |
385 | } else { | |
386 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) | |
387 | return &d->rx_sff[*can_id]; | |
0d66548a | 388 | } |
0d66548a OH |
389 | } |
390 | ||
391 | /* default: filter via can_id/can_mask */ | |
392 | return &d->rx[RX_FIL]; | |
393 | } | |
394 | ||
395 | /** | |
396 | * can_rx_register - subscribe CAN frames from a specific interface | |
397 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
398 | * @can_id: CAN identifier (see description) | |
399 | * @mask: CAN mask (see description) | |
400 | * @func: callback function on filter match | |
401 | * @data: returned parameter for callback function | |
402 | * @ident: string for calling module indentification | |
403 | * | |
404 | * Description: | |
405 | * Invokes the callback function with the received sk_buff and the given | |
406 | * parameter 'data' on a matching receive filter. A filter matches, when | |
407 | * | |
408 | * <received_can_id> & mask == can_id & mask | |
409 | * | |
410 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
411 | * filter for error frames (CAN_ERR_FLAG bit set in mask). | |
412 | * | |
1fa17d4b OH |
413 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
414 | * the callback function is running. The callback function must *not* free | |
415 | * the given sk_buff while processing it's task. When the given sk_buff is | |
416 | * needed after the end of the callback function it must be cloned inside | |
417 | * the callback function with skb_clone(). | |
418 | * | |
0d66548a OH |
419 | * Return: |
420 | * 0 on success | |
421 | * -ENOMEM on missing cache mem to create subscription entry | |
422 | * -ENODEV unknown device | |
423 | */ | |
424 | int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask, | |
425 | void (*func)(struct sk_buff *, void *), void *data, | |
426 | char *ident) | |
427 | { | |
428 | struct receiver *r; | |
429 | struct hlist_head *rl; | |
430 | struct dev_rcv_lists *d; | |
431 | int err = 0; | |
432 | ||
433 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
434 | ||
8b64056d OH |
435 | if (dev && dev->type != ARPHRD_CAN) |
436 | return -ENODEV; | |
437 | ||
0d66548a OH |
438 | r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); |
439 | if (!r) | |
440 | return -ENOMEM; | |
441 | ||
442 | spin_lock(&can_rcvlists_lock); | |
443 | ||
444 | d = find_dev_rcv_lists(dev); | |
445 | if (d) { | |
446 | rl = find_rcv_list(&can_id, &mask, d); | |
447 | ||
448 | r->can_id = can_id; | |
449 | r->mask = mask; | |
450 | r->matches = 0; | |
451 | r->func = func; | |
452 | r->data = data; | |
453 | r->ident = ident; | |
454 | ||
455 | hlist_add_head_rcu(&r->list, rl); | |
456 | d->entries++; | |
457 | ||
458 | can_pstats.rcv_entries++; | |
459 | if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) | |
460 | can_pstats.rcv_entries_max = can_pstats.rcv_entries; | |
461 | } else { | |
462 | kmem_cache_free(rcv_cache, r); | |
463 | err = -ENODEV; | |
464 | } | |
465 | ||
466 | spin_unlock(&can_rcvlists_lock); | |
467 | ||
468 | return err; | |
469 | } | |
470 | EXPORT_SYMBOL(can_rx_register); | |
471 | ||
0d66548a OH |
472 | /* |
473 | * can_rx_delete_receiver - rcu callback for single receiver entry removal | |
474 | */ | |
475 | static void can_rx_delete_receiver(struct rcu_head *rp) | |
476 | { | |
477 | struct receiver *r = container_of(rp, struct receiver, rcu); | |
478 | ||
479 | kmem_cache_free(rcv_cache, r); | |
480 | } | |
481 | ||
482 | /** | |
483 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
484 | * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list) | |
485 | * @can_id: CAN identifier | |
486 | * @mask: CAN mask | |
487 | * @func: callback function on filter match | |
488 | * @data: returned parameter for callback function | |
489 | * | |
490 | * Description: | |
491 | * Removes subscription entry depending on given (subscription) values. | |
492 | */ | |
493 | void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, | |
494 | void (*func)(struct sk_buff *, void *), void *data) | |
495 | { | |
496 | struct receiver *r = NULL; | |
497 | struct hlist_head *rl; | |
498 | struct hlist_node *next; | |
499 | struct dev_rcv_lists *d; | |
500 | ||
8b64056d OH |
501 | if (dev && dev->type != ARPHRD_CAN) |
502 | return; | |
503 | ||
0d66548a OH |
504 | spin_lock(&can_rcvlists_lock); |
505 | ||
506 | d = find_dev_rcv_lists(dev); | |
507 | if (!d) { | |
508 | printk(KERN_ERR "BUG: receive list not found for " | |
509 | "dev %s, id %03X, mask %03X\n", | |
510 | DNAME(dev), can_id, mask); | |
511 | goto out; | |
512 | } | |
513 | ||
514 | rl = find_rcv_list(&can_id, &mask, d); | |
515 | ||
516 | /* | |
517 | * Search the receiver list for the item to delete. This should | |
518 | * exist, since no receiver may be unregistered that hasn't | |
519 | * been registered before. | |
520 | */ | |
521 | ||
522 | hlist_for_each_entry_rcu(r, next, rl, list) { | |
f64f9e71 JP |
523 | if (r->can_id == can_id && r->mask == mask && |
524 | r->func == func && r->data == data) | |
0d66548a OH |
525 | break; |
526 | } | |
527 | ||
528 | /* | |
529 | * Check for bugs in CAN protocol implementations: | |
530 | * If no matching list item was found, the list cursor variable next | |
531 | * will be NULL, while r will point to the last item of the list. | |
532 | */ | |
533 | ||
534 | if (!next) { | |
535 | printk(KERN_ERR "BUG: receive list entry not found for " | |
536 | "dev %s, id %03X, mask %03X\n", | |
537 | DNAME(dev), can_id, mask); | |
538 | r = NULL; | |
0d66548a OH |
539 | goto out; |
540 | } | |
541 | ||
542 | hlist_del_rcu(&r->list); | |
543 | d->entries--; | |
544 | ||
545 | if (can_pstats.rcv_entries > 0) | |
546 | can_pstats.rcv_entries--; | |
547 | ||
548 | /* remove device structure requested by NETDEV_UNREGISTER */ | |
20dd3850 OH |
549 | if (d->remove_on_zero_entries && !d->entries) { |
550 | kfree(d); | |
551 | dev->ml_priv = NULL; | |
552 | } | |
0d66548a OH |
553 | |
554 | out: | |
555 | spin_unlock(&can_rcvlists_lock); | |
556 | ||
557 | /* schedule the receiver item for deletion */ | |
558 | if (r) | |
559 | call_rcu(&r->rcu, can_rx_delete_receiver); | |
0d66548a OH |
560 | } |
561 | EXPORT_SYMBOL(can_rx_unregister); | |
562 | ||
563 | static inline void deliver(struct sk_buff *skb, struct receiver *r) | |
564 | { | |
1fa17d4b OH |
565 | r->func(skb, r->data); |
566 | r->matches++; | |
0d66548a OH |
567 | } |
568 | ||
569 | static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) | |
570 | { | |
571 | struct receiver *r; | |
572 | struct hlist_node *n; | |
573 | int matches = 0; | |
574 | struct can_frame *cf = (struct can_frame *)skb->data; | |
575 | canid_t can_id = cf->can_id; | |
576 | ||
577 | if (d->entries == 0) | |
578 | return 0; | |
579 | ||
580 | if (can_id & CAN_ERR_FLAG) { | |
581 | /* check for error frame entries only */ | |
582 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) { | |
583 | if (can_id & r->mask) { | |
584 | deliver(skb, r); | |
585 | matches++; | |
586 | } | |
587 | } | |
588 | return matches; | |
589 | } | |
590 | ||
591 | /* check for unfiltered entries */ | |
592 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) { | |
593 | deliver(skb, r); | |
594 | matches++; | |
595 | } | |
596 | ||
597 | /* check for can_id/mask entries */ | |
598 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) { | |
599 | if ((can_id & r->mask) == r->can_id) { | |
600 | deliver(skb, r); | |
601 | matches++; | |
602 | } | |
603 | } | |
604 | ||
605 | /* check for inverted can_id/mask entries */ | |
606 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) { | |
607 | if ((can_id & r->mask) != r->can_id) { | |
608 | deliver(skb, r); | |
609 | matches++; | |
610 | } | |
611 | } | |
612 | ||
f706644d OH |
613 | /* check filterlists for single non-RTR can_ids */ |
614 | if (can_id & CAN_RTR_FLAG) | |
615 | return matches; | |
616 | ||
0d66548a OH |
617 | if (can_id & CAN_EFF_FLAG) { |
618 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) { | |
619 | if (r->can_id == can_id) { | |
620 | deliver(skb, r); | |
621 | matches++; | |
622 | } | |
623 | } | |
624 | } else { | |
625 | can_id &= CAN_SFF_MASK; | |
626 | hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) { | |
627 | deliver(skb, r); | |
628 | matches++; | |
629 | } | |
630 | } | |
631 | ||
632 | return matches; | |
633 | } | |
634 | ||
635 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
636 | struct packet_type *pt, struct net_device *orig_dev) | |
637 | { | |
638 | struct dev_rcv_lists *d; | |
7f2d38eb | 639 | struct can_frame *cf = (struct can_frame *)skb->data; |
0d66548a OH |
640 | int matches; |
641 | ||
1758c094 OH |
642 | if (!net_eq(dev_net(dev), &init_net)) |
643 | goto drop; | |
0d66548a | 644 | |
1758c094 OH |
645 | if (WARN_ONCE(dev->type != ARPHRD_CAN || |
646 | skb->len != sizeof(struct can_frame) || | |
647 | cf->can_dlc > 8, | |
648 | "PF_CAN: dropped non conform skbuf: " | |
649 | "dev type %d, len %d, can_dlc %d\n", | |
650 | dev->type, skb->len, cf->can_dlc)) | |
651 | goto drop; | |
7f2d38eb | 652 | |
0d66548a OH |
653 | /* update statistics */ |
654 | can_stats.rx_frames++; | |
655 | can_stats.rx_frames_delta++; | |
656 | ||
657 | rcu_read_lock(); | |
658 | ||
659 | /* deliver the packet to sockets listening on all devices */ | |
660 | matches = can_rcv_filter(&can_rx_alldev_list, skb); | |
661 | ||
662 | /* find receive list for this device */ | |
663 | d = find_dev_rcv_lists(dev); | |
664 | if (d) | |
665 | matches += can_rcv_filter(d, skb); | |
666 | ||
667 | rcu_read_unlock(); | |
668 | ||
62bcaa13 OH |
669 | /* consume the skbuff allocated by the netdevice driver */ |
670 | consume_skb(skb); | |
0d66548a OH |
671 | |
672 | if (matches > 0) { | |
673 | can_stats.matches++; | |
674 | can_stats.matches_delta++; | |
675 | } | |
676 | ||
6ca8b990 | 677 | return NET_RX_SUCCESS; |
1758c094 OH |
678 | |
679 | drop: | |
680 | kfree_skb(skb); | |
6ca8b990 | 681 | return NET_RX_DROP; |
0d66548a OH |
682 | } |
683 | ||
684 | /* | |
685 | * af_can protocol functions | |
686 | */ | |
687 | ||
688 | /** | |
689 | * can_proto_register - register CAN transport protocol | |
690 | * @cp: pointer to CAN protocol structure | |
691 | * | |
692 | * Return: | |
693 | * 0 on success | |
694 | * -EINVAL invalid (out of range) protocol number | |
695 | * -EBUSY protocol already in use | |
696 | * -ENOBUF if proto_register() fails | |
697 | */ | |
1650629d | 698 | int can_proto_register(const struct can_proto *cp) |
0d66548a OH |
699 | { |
700 | int proto = cp->protocol; | |
701 | int err = 0; | |
702 | ||
703 | if (proto < 0 || proto >= CAN_NPROTO) { | |
704 | printk(KERN_ERR "can: protocol number %d out of range\n", | |
705 | proto); | |
706 | return -EINVAL; | |
707 | } | |
708 | ||
a2fea5f1 UT |
709 | err = proto_register(cp->prot, 0); |
710 | if (err < 0) | |
711 | return err; | |
712 | ||
1ca050d9 OH |
713 | mutex_lock(&proto_tab_lock); |
714 | ||
0d66548a OH |
715 | if (proto_tab[proto]) { |
716 | printk(KERN_ERR "can: protocol %d already registered\n", | |
717 | proto); | |
718 | err = -EBUSY; | |
53914b67 | 719 | } else |
a9b3cd7f | 720 | RCU_INIT_POINTER(proto_tab[proto], cp); |
a2fea5f1 | 721 | |
1ca050d9 | 722 | mutex_unlock(&proto_tab_lock); |
0d66548a | 723 | |
0d66548a | 724 | if (err < 0) |
a2fea5f1 | 725 | proto_unregister(cp->prot); |
0d66548a OH |
726 | |
727 | return err; | |
728 | } | |
729 | EXPORT_SYMBOL(can_proto_register); | |
730 | ||
731 | /** | |
732 | * can_proto_unregister - unregister CAN transport protocol | |
733 | * @cp: pointer to CAN protocol structure | |
734 | */ | |
1650629d | 735 | void can_proto_unregister(const struct can_proto *cp) |
0d66548a OH |
736 | { |
737 | int proto = cp->protocol; | |
738 | ||
1ca050d9 OH |
739 | mutex_lock(&proto_tab_lock); |
740 | BUG_ON(proto_tab[proto] != cp); | |
a9b3cd7f | 741 | RCU_INIT_POINTER(proto_tab[proto], NULL); |
1ca050d9 OH |
742 | mutex_unlock(&proto_tab_lock); |
743 | ||
744 | synchronize_rcu(); | |
a2fea5f1 UT |
745 | |
746 | proto_unregister(cp->prot); | |
0d66548a OH |
747 | } |
748 | EXPORT_SYMBOL(can_proto_unregister); | |
749 | ||
750 | /* | |
751 | * af_can notifier to create/remove CAN netdevice specific structs | |
752 | */ | |
753 | static int can_notifier(struct notifier_block *nb, unsigned long msg, | |
754 | void *data) | |
755 | { | |
756 | struct net_device *dev = (struct net_device *)data; | |
757 | struct dev_rcv_lists *d; | |
758 | ||
721499e8 | 759 | if (!net_eq(dev_net(dev), &init_net)) |
0d66548a OH |
760 | return NOTIFY_DONE; |
761 | ||
762 | if (dev->type != ARPHRD_CAN) | |
763 | return NOTIFY_DONE; | |
764 | ||
765 | switch (msg) { | |
766 | ||
767 | case NETDEV_REGISTER: | |
768 | ||
20dd3850 | 769 | /* create new dev_rcv_lists for this device */ |
0d66548a OH |
770 | d = kzalloc(sizeof(*d), GFP_KERNEL); |
771 | if (!d) { | |
772 | printk(KERN_ERR | |
773 | "can: allocation of receive list failed\n"); | |
774 | return NOTIFY_DONE; | |
775 | } | |
20dd3850 OH |
776 | BUG_ON(dev->ml_priv); |
777 | dev->ml_priv = d; | |
0d66548a OH |
778 | |
779 | break; | |
780 | ||
781 | case NETDEV_UNREGISTER: | |
782 | spin_lock(&can_rcvlists_lock); | |
783 | ||
20dd3850 | 784 | d = dev->ml_priv; |
0d66548a | 785 | if (d) { |
20dd3850 | 786 | if (d->entries) |
0d66548a | 787 | d->remove_on_zero_entries = 1; |
20dd3850 OH |
788 | else { |
789 | kfree(d); | |
790 | dev->ml_priv = NULL; | |
791 | } | |
0d66548a OH |
792 | } else |
793 | printk(KERN_ERR "can: notifier: receive list not " | |
794 | "found for dev %s\n", dev->name); | |
795 | ||
796 | spin_unlock(&can_rcvlists_lock); | |
797 | ||
0d66548a OH |
798 | break; |
799 | } | |
800 | ||
801 | return NOTIFY_DONE; | |
802 | } | |
803 | ||
804 | /* | |
805 | * af_can module init/exit functions | |
806 | */ | |
807 | ||
808 | static struct packet_type can_packet __read_mostly = { | |
09640e63 | 809 | .type = cpu_to_be16(ETH_P_CAN), |
0d66548a OH |
810 | .dev = NULL, |
811 | .func = can_rcv, | |
812 | }; | |
813 | ||
ec1b4cf7 | 814 | static const struct net_proto_family can_family_ops = { |
0d66548a OH |
815 | .family = PF_CAN, |
816 | .create = can_create, | |
817 | .owner = THIS_MODULE, | |
818 | }; | |
819 | ||
820 | /* notifier block for netdevice event */ | |
821 | static struct notifier_block can_netdev_notifier __read_mostly = { | |
822 | .notifier_call = can_notifier, | |
823 | }; | |
824 | ||
825 | static __init int can_init(void) | |
826 | { | |
827 | printk(banner); | |
828 | ||
20dd3850 OH |
829 | memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list)); |
830 | ||
0d66548a OH |
831 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), |
832 | 0, 0, NULL); | |
833 | if (!rcv_cache) | |
834 | return -ENOMEM; | |
835 | ||
0d66548a OH |
836 | if (stats_timer) { |
837 | /* the statistics are updated every second (timer triggered) */ | |
838 | setup_timer(&can_stattimer, can_stat_update, 0); | |
839 | mod_timer(&can_stattimer, round_jiffies(jiffies + HZ)); | |
840 | } else | |
841 | can_stattimer.function = NULL; | |
842 | ||
843 | can_init_proc(); | |
844 | ||
845 | /* protocol register */ | |
846 | sock_register(&can_family_ops); | |
847 | register_netdevice_notifier(&can_netdev_notifier); | |
848 | dev_add_pack(&can_packet); | |
849 | ||
850 | return 0; | |
851 | } | |
852 | ||
853 | static __exit void can_exit(void) | |
854 | { | |
20dd3850 | 855 | struct net_device *dev; |
0d66548a OH |
856 | |
857 | if (stats_timer) | |
d9e64f83 | 858 | del_timer_sync(&can_stattimer); |
0d66548a OH |
859 | |
860 | can_remove_proc(); | |
861 | ||
862 | /* protocol unregister */ | |
863 | dev_remove_pack(&can_packet); | |
864 | unregister_netdevice_notifier(&can_netdev_notifier); | |
865 | sock_unregister(PF_CAN); | |
866 | ||
20dd3850 OH |
867 | /* remove created dev_rcv_lists from still registered CAN devices */ |
868 | rcu_read_lock(); | |
869 | for_each_netdev_rcu(&init_net, dev) { | |
870 | if (dev->type == ARPHRD_CAN && dev->ml_priv){ | |
871 | ||
872 | struct dev_rcv_lists *d = dev->ml_priv; | |
873 | ||
874 | BUG_ON(d->entries); | |
875 | kfree(d); | |
876 | dev->ml_priv = NULL; | |
877 | } | |
0d66548a | 878 | } |
20dd3850 | 879 | rcu_read_unlock(); |
0d66548a | 880 | |
382bfeec JDB |
881 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
882 | ||
0d66548a OH |
883 | kmem_cache_destroy(rcv_cache); |
884 | } | |
885 | ||
886 | module_init(can_init); | |
887 | module_exit(can_exit); |